Proposal #3339: Add (+>) as a synonym for mappend

Yitzchak Gale gale at
Mon Aug 15 12:14:08 CEST 2011

Edward Kmett wrote:
> I was currently planning on leaving the <> in semigroups untouched...
> if (<>) is just a method exported by the module then the packages I have
> that import just Monoid(..) from Data.Monoid won't change.

Hmm, why not? If two different functions named <> are imported
via Monoid(..) and Semigroup(..), I don't think the compiler
will find that humorous. Are you going to use qualified operators?

> If I have to go through and choose a different operator for it, I go from
> having to make (based on grep) about 130 import statement changes that I can
> mostly automate with perl, followed by losing a few hours pushing packages,
> to having instead to make literally thousands of laborious changes where I
> have to carefully examine every one.

Yes, I am also facing days of tedious work to dig out of this.
I would love to find automation opportunities, but I don't understand
how what you are suggesting can help. I'd also like to coordinate
and do things in a standard way as much as possible, to salvage
as much readability as we can.


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